Apparatus for energizing an audion circuit



G. B. CROUSE APPARATUS FOR ENERGIZING AN AUDION CIRCUIT Filed Jan. 19, 1928 by. O M

3 application Patented 113, i931 .PORATI mo -NE Yo'nx, N. A CORPQRATIONOF N W Y R I APPABIQTWI 1 .weem; e lwni CIRCUIT .Ap iicatmnuea January 19, 923. iS erla1 Ne. 247,952.

"This invention relatesto apparatus forienergizing an audion circuit -and more particularlyto a'filter for use between a'source of rectified current and adire'ct currentload circuit, suchas the.

circuit or circuits ofan audion amplifier; i

The filter; networlr is of the samegeneral typeand has the. samesuppression characten istic as thefilter described in fmy copending Serial No. 6 80,096, filed Decem her-19, 1923. 1

audion circuits requiring substantially pure direct current arearranged in an arm con-- jugate to a sour'ce of-rectifie'd current, wh1le another audion 'circult which requires; less freedom from alternating components is nonconjugate to the source. I

These and other objects of the invention will be apparent from the following speci 1. 1a fication; when taken with the .accompanymg drawing, in which the single 'view is a schematic diagram of one embodiment of tl1e"invention.

. In the drawing numerals 1 and 2, identify l the terminals forconnecting' the primary. winding oia transformer to an alternating} current light-orpower system. .The. trans-'5 former has an iron core 4 and a secondary v winding-5 which istapped at the middle fora; yi connection'in the usual waywith a full wave." rectifier 6'. The usual bufl'ercondensers 7 and; 8 are connected across the'sections of thesecondary Winding for eliminating radio .frequency radiation. A condenser 91s shunted v ia-across the leads 10 and 11 which 'passuthe rectified pulsating direct current to the filter mesh. I I l "The impedances of the ranged in the-formof a Wheatstone: bridge mi'having conjugatepairsoi' terminals. to which employed, a full wave rectifier the balanced for the IQO cycIe'fundamental, but with .a -cyc1e power nomical 'constructio-n will usually be obtained; when the bridge is-balanced-for components The network will not filter mesh are ar GEORGE 1i. mo se, 'orjwoom jiinmwjimmjlssmnom conimacnousn con-,

the rectified current leads 10, l land certain I the audion circuits; respectively,-

pure resistances 12 and 13,

value: of arm B being generally greater than one common core .17.

J; The "bridge networkis so designed that the ratio ofthe impedance of. the induictanc'elt minus the impedance of the. condenser 15t0 the impedance of; the. inductance-1,16 i'sgequal to theiratio of the resistance 12 to, the resistance13 at-the. frequency'of the. most disturb-"- ing. alternating component passed by the rectifier 6. The most disturbing. componentmay or may .not be the fundamental frequency, dependmgupQn the frequencyof the sourceof alternating. currentrand the type supply .a more eco-.

of 150, cycle current.

may be con-v nected; The arms A and B are formed by the respectively, the

[that 10f arm 'A The 'balancingarm' C is- 7 formed the inductance l4 in'series with the capacity"15, while' arm D is -'-formed by the; inductance 16, the inductances being. wound.

r6 of rectifier Vith a cycle power'supply and. v

bridgeis preferably be perfectly'balanced at other. frequencies. 7

but thedegree of unbalancemay be made negligibly small by making the impedance of. the inductances 14, 'lfirelatively high in,

comparisonwwith' the impedance .of the;con i denser..15;. Forcertain uses where substantially plete suppression of alternatingcomponents ;1s required the effectiveresistancejof the du ctances 14, 16 mustlbeconsidered, and the I ratio of their efiective resistancesshould bef the'sarne; as the ratioof the resistances '12 and ,13. -.The positive terminal 18. of the: aud1on;' circuits is "preferably adjustable througha small range for Varyingrtheratio turing variations. L a

. The. direct current output terminals 18,. 19 are connected by an alternatingcurrent path:

comprising in'series the resistances 20, 21 andthe condenser 22 which connects, the-outer ends of theresistances. Leadsare connected ofarms 12 and "18 to correct for manufacdiate point and the inner end of theresistance 20 to appropriate terminals on the radio grid bias voltages; 2d are connected bereceiver for supplying By-pass condensers 23,

tween the bridge terminals 18, 19, respectively, and the -B lead.

The plate voltage to be applied to the audion o1 the power stage oi the receiver does not require the degree of filtering which is essential in the preliminary stages, since any ripple effect in the output of the power stage is not further amplified. The plate circuit of the power stage may be connected by the lead 180 V to the junction of inductance 1a and condenser 15 in the bridge arm C which lies between the positive source lead 10 and the negative direct current terminal 19.

Itis to be understood that the network may be designed to deliver voltages of any desired magnitudes and that the use of legends such as 90 V is not intended to limit the invention to apparatus supplying the particular voltages indicated by the several legends. .Vhen direct current power lines of appropriate voltage are available the transformer and rectifier may, of course, be eliminated as the direct current generators rectify the alternating current to deliver it to the power lines. The rectified current lead lines 10, 11 may be connected across the direct current power lines and the impedances of the bridge arms. designed to effect a maximum suppression of the most disturbing alternating component by balancing the bridge at the frequency of that component.

It will be apparent that the inventionis not limited to the specific construction illustrated in the drawings as various changes may be made without departing from the spirit of my invention as set forth in the fol- The particular modificationlowing claims. shown in the drawings is designed to supply plate and grid bias voltages, but it will be apparentthat the same construction may be employed'to supply filament and grid voltages by an appropriate choice of the impedances constituting the bridge network.

I claim:

1. In apparatus for energizing an audion circuit from a source of rectified current, a plurality of impedances arranged as an alternating current /Vheatstone bridge across which said source and said circuit may be connected as conjugate arms, the impedances forming two adjacent arms being resistive,

and the other two arms comprising an inductance, and an inductance in series with a capacity, respectively.

2. In apparatus for energizing an audion circuit from a source or rectified current, a plurality of parallel paths connected across said source, one or" said paths comprising a res stance and the other path comprising a pair of lnductances connected to the respective terminals of said source and a capacity joining said inductances, the condenser ter minal of one inductance and an intermediate point ot'said resistance serving as terminals for saidaudion circuit. j

i 3. In a filter network for use between a source of rectified current and an audion circuit, a plurality of impedances arranged as an alternating current Wheatstone bridge network across which said source and said circuit are arranged as the conjugate arms thereof, a pair of adjacent bridge arms being resistive impedances and the remaining pair or bridge arms each including an inductive impedance, the ratio of the impedances of said inductive impedances at the frequency of an alternating component present in the rectified current being substantially the same as the ratio of the resistances of the said resistive impedances.

4. A filter network for use between a source of rectified current and an audion amplifier, said network comprisinga plurality of impedances arranged in an alternating current 'iVheatstone bridge and having a pair of input and of output terminals across which said source and said audion amplifier may be connected as conjugate arms, and a resistance having one end connected to the negative output terminal, whereby said resistance may provide a negative grid bias potential when theaudion filament is connected to the other end of said resistance.

a 5. In apparatus for energizing from a source of rectified current a pair of audion circuits having dissimilar voltage requirements, a plurality of impedances arranged as an alternating current Wheatstone bridge having input terminals for connection to said source and output terminals across which there is substantially no difference in alternating current potentials, a resistance having an end connected to one of said output terminals, a second resistance having an end connected to the other output terminal, and means for connecting the audion circuits between spaced points on the respective resistances. a

6. A filter network for use between a source of rectified current and a plurality of audion grid and plate circuits, and of the type comprising a plurality of impedances arrange as an alternating current l Vheatstone bridge, characterized by the fact that between the audion circuit terminals of said bridge network there are serially arranged a resistance,

network effects a maximum suppression at a a capacity, and a second resistance, and means for connecting plate circuits of different voltage requirements to the resistance adjacent the positive audion circuit terminal, and

means for connecting grid circuit of different voltage requirements tothe resistance; adja cent the negative audlon c1rcu1t terminal.

7. In apparatus for energizing a plurality of audition circuits from a source of rectified current, a plurality of impedances arranged as a Wheatstone bridge having conjugate pairs of terminals forconnection to said source and said circuits, respectively, and a path between said circuit terminals comprising a pair of resistances in series with and at opposite sides of a condenser, the condenser end of r the resistance connected to the negative cir-i cuit terminal of the bridge serving as a common terminal for all of sald circuits, and condensers between the respective circuittermi-a nals of the bridgev network and the said common terminah' 8. In apparatus for energizng a pluralty of audion circuits from a source of rectified, current, a condenser and an impedance. network adapted to be connected in parallel across said source, said network having a pair of output terminals across whlch one-of said circuits may be connected, the impedances between said source and said output terminals being so proportioned and related that the finite frequency within the lower range of frequencies passed by said rectifier, and means for connecting another audion circuit across a part of said networkythe impedance between said rectifier and the said other circuit cooperating with saidjcondens er to form a filter mesh. I I

9. In apparatus for energizing a plurality of audion circuits'from a source of rectified current, a plurality of impedances arranged as a wheatstone bridge across which said source and one of said circuits are connected as the conjugate arms thereof, and means for connecting another of said circuits whichorequires less freedom from alternating current components across a portion of the bridge which is non-conjugate to said source.

10. The invention as set forthin cliam 9, wherein said audion circuits has a terminal in common.

11. The invention as set forth in claim 9,

in combination with a condenser shunted across said source, the bridge arm between the positive source terminal and the negative circuit terminal comprising in series an inductance adjacent said source terminal and a condenser adjacent said circuit terminal,

the said other audion circuit being connected across said condenser. a

In testimony whereof, I afiix my signature.

enonen ncnousn, 

